I am also teaching it tomorrow and I would like to know what happens when the citric acid hits the warmed milk. What is the purpose of adding the citric acid. It slightly curdles the milk but it sort of sets the milk too. Then of course the rennet is added and that sets really quickly as well.

I don't always understand cheese making but I can sure make the cheese!

This dynamic forms the core action of cheesemaking prior to aging. Let's review.

- Casein, a milk protein, consists of micellar structures formed of casein subtypes grouped together, with a k-casein end that has a negative charge due to the carbohydrate end that tends to protrude out, giving each micellar structure stability to be liquid.- As you add acid, it degrades both that hydrophilic carb "leg" of micelles, and the calcium phosphate bonds within micelles. The first helps with the set, and the second helps with the stretch and plasticization upon heating.- Rennet works faster at lower pH levels, with an optimal or around 5.5.

So it's like you said. Acid helps to start the process, and rennet fosters enzymatic cleaving.

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Stick to the basics if what I wrote is too jumbled up. Milk has a lot of protein. That protein needs to be "softened up" or it will not stretch when in curd form. And the acid is what softens it up. So you can either soften it up after making the curd by waiting, or do it beforehand with acid in the milk.

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I had my class today and it went really well. We made a cultured mozzarella that took approx 5 hours from start to finish. Its a Carole Willman recipe, adding a thermo culture wait an hour before adding rennet... (I have posted the recipe on this forum before).

While we waited for the thermo to work we made Rickki's 30 min mozz and that worked a treat. I love the looks on everyones faces when the curd starts stretching. Mind you I have so much stress hoping it will all work well. I have had one brand of local organic unhomogenised milk not work.

I wonder whether that is a safe food requirement. I will find out.Unfortunately the only unhomogenised milk readily available is organic. Luckily a local dairy is about to legally sell unhomog milk and I will be keen to use that.

Just to let you know I have since made the 30 minute mozzarella almost 100 times now as I teach and demonstrate this method on a regular basis plus make it at home.

The trick is to CHECK THE USE BY DATE OF THE CITRIC ACID!!. Most people pull the citric acid out of the pantry thinking "I have this in the pantry". It will be 7 years out of date! Buy a new batch and then try it.

Organic milk is almost always ultra-pasteurized and not a good choice for making cheese

I am guessing this is true in the USA, but not necessarily the case in other parts of the world. For example, not the norm in the UK. I see you are in NSW, so might want to check with a local source on Australian standards for treatment of organic milk. Hope this helps.

The information I have found indicates that often organic products sit on the shelf longer, as they are more of a 'specialty' product. As such MOST dairy's choose to Ultra pasturize to extend shelflife on the organic milk, and have less waste, again this is not a requirement its a 'smart' money saving business practice for the dairy and the retailer.

LOL yeah I never even thought of that Bbracken!! But if it sells your product use it right LOL

I am not sure about other places but I know here Organic is WAY more expensive, and it makes me chuckle because you read about how its better for the environment, can be/is as effective at production as conventional, and so ultimatley without pesticieds and fertilizers and.. I would think you would be able to produce a cheaper product, that would be able to sell more and then eliminate the waste aspect as its not sitting on shelves, Another athread I read soem one was paying between $4-$16, the less processed the less human involvement meant the price 4x!!

There is certification to consider, not to mention for larger productions it is really more difficult to go organic....the easy way out is growth hormones, antibiotics etc.

I moved to the country in the early 90s and went organic with my garden. Meant more work, but was very doable on a small scale...I did, however, appreciate how difficult it would be for a large farm to go organic. After 3 years the results were phenomenal! I was getting more results (and better) from half the space my neighbors were planting. They thought I was a nut until that 3rd year...then they were amazed.